Study Nedarim folio 17A with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
Text Excerpt
תלמוד לומר: ״להרע או להיטיב״. מה הטבה רשות, אף הרעה רשות. יצא נשבע לבטל את המצוה ולא ביטל — שאין הרשות בידו!
However, the verse states: “Or if anyone swears clearly with his lips to do evil, or to do good” (Leviticus 5:4). From the juxtaposition of evil and good it is derived that just as the doing of good, which is interpreted as obligating himself to take a positive action, is referring to a permitted activity, e.g., to eat, so too, the doing of evil, which is interpreted as prohibiting himself from something, refers only to that which is permitted, e.g., not to eat. This excludes one who takes an oath to nullify a mitzva and does not nullify it; he is not liable for violating the oath, as the permission to nullify it is not in his power.
חד קרא למיפטריה מקרבן שבועה, וחד למיפטריה מן לאו דשבועה.
The Talmud answers that both verses are necessary. One verse: “To do evil or to do good,” which is stated in the context of the halakhot of offerings, is necessary to exempt him from bringing an offering for violating an oath, and one verse: “He should not profane,” is necessary to exempt him from the prohibition for violating an oath.
מתני׳ יש נדר בתוך נדר, ואין שבועה בתוך שבועה. כיצד? אמר: ״הריני נזיר אם אוכל״, ״הריני נזיר אם אוכל״, ואכל — חייב על כל אחת ואחת. ״שבועה שלא אוכל״, ״שבועה שלא אוכל״, ואכל — אינו חייב אלא אחת.
Mishnah: There is a vow within a vow. It is possible to impose an additional prohibition, by means of a vow, on an item that is already forbidden by means of a vow. But there is no oath within an oath. If one takes an oath twice with regard to the same action, the second oath does not take effect. How so? If one said: I am hereby a nazirite if I eat, and then repeated: I am hereby a nazirite if I eat, and then he ate, he is obligated to observe naziriteship for 30 days for each and every one of the vows, as both vows took effect. However, if he said: I hereby take an oath that I will not eat, and repeated: I hereby take an oath that I will not eat, and then he ate, he is liable to bring an offering for only one violation of an oath.